An electric timepiece with a solar cell using power generated by the solar cell as a timepiece driving source has been known. In one example, the solar cell is disposed behind a light-permeable dial or at substantially right angle outside a light-permeable dial trim ring disposed around an outer circumference of a surface of the dial. However, the solar cell disposed as described above allows navy color of the solar cell to be seen through the dial or the dial trim ring, resulting in deterioration in an aesthetic aspect.
Along with recent improvement in a power generation performance of a solar cell and a progress in a technology of lowering power consumption for driving a timepiece, a power generation amount sufficient for driving a timepiece can be obtained with the structure in which the solar cell is disposed behind the light-permeable dial even though the dial is semi-permeably decorated. Such a decorated dial makes the solar cell indistinctive to satisfy the aesthetic aspect.
In contrast, in the structure in which the solar cell is disposed at substantially right angle outside the light-permeable dial trim ring disposed in the outer circumference of the surface of the dial, the light-permeable dial trim ring has a three-dimensional shape. It is therefore difficult for the dial trim ring to be semi-permeably decorated.
Patent Literature 1 discloses, as an example of semi-permeably decorating the dial trim ring, a structure in which a metal thin film layer is formed in the inner circumference surface of the light-permeable dial trim ring, and a coloring material or a fluorescent material and a light diffusion material are blended in the material of the dial trim ring. This structure makes the semi-permeable dial trim ring to be seen as a metal color, and the power generation amount sufficient for driving the timepiece is obtained with this structure.